 .game-num {
 	width: 0px;
 	height: 0px;
 	color: #fff;
 	font-size: 40px;
 	position: absolute;
 }

 .game-num-2 {
 	background: #eee4da;
 	color: #776e65;
 }

 .game-num-4 {
 	background: #ede0c8;
 	color: #776e65;
 }

 .game-num-8 {
 	background: #f2b179;
 }

 .game-num-16 {
 	background: #f59563;
 }

 .game-num-32 {
 	background: #f67c5f;
 }

 .game-num-64 {
 	background: #f65e3b;
 }

 .game-num-128 {
 	background: #edcf72;
 	font-size: 35px;
 }

 .game-num-256 {
 	background: #edcc61;
 	font-size: 35px;
 }

 .game-num-512 {
 	background: #9c0;
 	font-size: 35px;
 }

 .game-num-1024 {
 	background: #33b5e5;
 	font-size: 30px;
 }

 .game-num-2048 {
 	background: #09c;
 	font-size: 30px;
 }

 /* 九宫格 */
 #game_container {
 	width: 440px;
 	/* 4 * 100px (单元格大小) + 5 * 20px (间距) */
 	height: 440px;
 	background-color: #bbada0;
 	border-radius: 10px;
 	position: relative;
 	margin: 0 auto;
 	/* 水平居中 */
 }

 .game-cell {
 	width: 100px;
 	height: 100px;
 	border-radius: 6px;
 	background-color: #ccc0b3;
 	position: absolute;
 }

 /* 重新开始 */
 #game_over {
 	text-align: center;
 	margin-top: 20px;
 }

 #game_restart {
 	display: inline-block;
 	padding: 10px 20px;
 	background-color: #8f7a66;
 	color: #fff;
 	border: none;
 	border-radius: 4px;
 	cursor: pointer;
 	font-size: 16px;
 	transition: background-color 0.3s ease;
 	box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
 }

 #game_restart:hover {
 	background-color: #6c5b4c;
 }

 #game_restart:active {
 	background-color: #574a3d;
 	box-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
 	transform: translateY(1px);
 }

 /* 分数 */
 #game {
 	text-align: center;
 	margin-bottom: 20px;
 }

 #game_score {
 	font-size: 24px;
 	font-weight: bold;
 }